Recently, an armrest of a seat installed on aircraft or a vehicle, capable of housing a TV set for personal use has been proposed. FIG. 21 shows such a known armrest 51. The armrest 51 is provided with two adjoining cavities 54 under a cocktail tray 52 formed in the front portion of its upper wall to house two TV sets 53, respectively. A hinge mechanism 56 fixedly holding a turning mechanism 55 is provided on the armrest 51 at the front end of each cavity 54 so as to turn the turning mechanism 55 thereon between the interior and exterior of the cavity 54. The TV set is supported by the turning mechanism 55 so as to be tilted in all directions.
The hinge mechanism 56 is provided with a locking mechanism 57 as shown in FIG. 22. The locking mechanism 57 locks the TV set 53 at either a housing position or an operating position by inserting a locking pin 58 through a knuckle part 56a of the hinge mechanism 56 in a through hole 56c formed in one end of a hinge pin 56b. Thus, the turning mechanism 55 can be turned together with the hinge mechanism 56 substantially through an angle of 180.degree. relative to the opening of the cavity 54, and the turning mechanism 55 can be locked at both the housing position and the operating position.
Thus, the TV set can be held fixedly at the operating position by inserting the extremity of the locking pin 58 through the knuckle part 56a of the hinge mechanism 56 in the through hole 56c formed in the hinge pin 56b. However, if the TV set 53 is set free at the operating position without inserting the locking pin 58 in the through hole 56c, the TV set 53 will be turn downward by gravity. Consequently, the TV set 53 may be subjected to shocks and wrecked or the fingers of the viewer may be injured by being caught between the TV set 53 and the armrest 51.
As shown in FIG. 23, the turning mechanism 55 comprises a tubular support post 61 ending in a semispherical socket 60 provided with a recess 59 in its upper portion, and a stem 63 ending in a ball 62 received in the recess 59 for turning in all directions in the recess 59 to adjust the orientation and position of the TV set 53 supported on the turning mechanism 55. The stem 62 can be revolved through an angle of 360.degree. about the axis of the semispherical socket 60. However, if the gripping force of the semispherical socket 60 decreases, the turning mechanism 55 is unable to hold the TV set 53 securely in place, so that the TV set 53 may be tilted undesirably in directions indicated by arrows x or in directions indicated by arrows y to dislocate the display unit 64 of the TV set from an appropriate position.
Furthermore, if the gripping force of the semispherical socket 60 is enhanced to support the TV set 53 firmly, an increased frictional force acting between the semispherical socket 60 and the ball 62 of the stem 63 makes the positional adjustment of the TV set difficult.
The present invention has been made in view of the foregoing problems and it is therefore an object of the present invention to provide a TV set supporting structure incorporating a shock absorbing mechanism capable of preventing the accidental drop of a TV set supported thereon in turning the TV set from the operating position to the housing position.
It is another object of the present invention to provide a TV set supporting structure capable of securely holding a TV set supported thereon at the operating position.